Effect of high-nitrogen fertilizer on gliadin and glutenin subproteomes during kernel development in wheat (Triticum aestivum L.)

Nitrogen (N), a macronutrient essential for plant growth and development, is needed for biosynthesis of protein and starch, which affect grain yield and quality. Application of high-N fertilizer increases plant growth, grain yield, and flour quality. In this study, we performed the first comparative analysis of gliadin and glutenin subproteomes during kernel development in the elite Chinese wheat cultivar Zhongmai 175 under high-N conditions by reversed-phase ultra-performance liquid chromatography and two-dimensional difference gel electrophoresis (2D-DIGE). Application of high-N fertilizer led to significant increases in gluten macropolymer content, total gliadin and glutenin content, and the accumulation of individual storage protein components. Of 126 differentially accumulated proteins (DAPs) induced by high-N conditions, 24 gliadins, 12 high-molecular-weight glutenins, and 27 low-molecular-weight glutenins were significantly upregulated. DAPs during five kernel developmental stages displayed multiple patterns of accumulation. In particular, gliadins and glutenins showed respectively five and six accumulation patterns. The accumulation of storage proteins under high-N conditions may lead to improved dough properties and bread quality.